Procedure for Particle Size Distribution in Suspensions

1) Purpose

The purpose of this SOP is to outline the procedure for determining the particle size distribution in pharmaceutical suspensions to ensure product quality and consistency.

2) Scope

This SOP applies to all pharmaceutical suspensions manufactured within the facility that require particle size distribution testing as part of quality control.

3) Responsibilities

Quality Control (QC) Department: Responsible for conducting particle size distribution testing and ensuring compliance with this SOP.
Production Department: Responsible for providing suspension samples and supporting QC during testing.

4) Procedure

4.1 Equipment Preparation:
    4.1.1 Verify and calibrate the particle size analyzer according to manufacturer’s instructions.
    4.1.2 Ensure adequate supply of dispersant, cleaning solutions, and calibration standards.
    4.1.3 Perform instrument suitability checks using standard particles before testing.

4.2 Sample Preparation:
    4.2.1 Obtain representative samples of suspensions from different batches.
    4.2.2 Homogenize the suspension thoroughly using a suitable method to ensure uniform distribution.
    4.2.3 Dilute the suspension if necessary to achieve optimal measurement conditions.

4.3 Particle Size Measurement:
    4.3.1 Set the particle size analyzer parameters (e.g., measurement range, analysis mode) based on sample characteristics.
    4.3.2 Disperse the suspension in the dispersant solution according to the analyzer’s operating procedure.
    4.3.3 Perform particle size analysis and obtain size distribution data from the analyzer software.
    4.3.4 Repeat measurements as necessary to ensure accuracy and reproducibility.

4.4 Interpretation of Results:
    4.4.1 Analyze particle size distribution data to determine the mean particle size, size range, and distribution pattern.
    4.4.2 Compare measured results against acceptance criteria specified in pharmacopeial standards or internal specifications.
    4.4.3 Document particle size distribution results accurately, including any deviations from expected values.
    4.4.4 Investigate and resolve discrepancies or out-of-specification results promptly.

4.5 Acceptance Criteria:
    4.5.1 Suspensions are considered acceptable if their particle size distribution meets predefined limits for the intended use.
    4.5.2 Ensure all particle size measurements adhere to validated procedures and method validation parameters.

4.6 Documentation:
    4.6.1 Record all particle size distribution testing procedures, results, and observations in the Particle Size Distribution Report.
    4.6.2 Maintain detailed records of sample details, testing conditions, equipment calibration, and any corrective actions taken.
    4.6.3 Review and approve the documentation by QC Manager.

5) Abbreviations, if any

QC: Quality Control

6) Documents, if any

Particle Size Distribution Report
Particle Size Analyzer Calibration Certificates
Sampling Plan Document

7) Reference, if any

USP General Chapter <429> – Light Diffraction Measurement of Particle Size
Pharmacopeial standards for Particle Size Distribution in Suspensions

8) SOP Version

Version 1.0